Elastomeric thermoplastic molding materials and their preparation

Abstract

Elastomeric thermoplastic molding materials contain (A) from 5 to 50 parts by volume of a partially or completely crystalline thermoplastic polymer having a melting point of above 160° C., as a coherent phase, and (B) from 95 to 50 parts by volume of one or more crosslinked elastomeric polymers which are prepared by emulsion polymerization, are dispersed in the component A and have a glass transition temperature Tg of below -10° C., the sum of A and B being 100 parts by volume, with the proviso that the mixture of A and B has a Vicat softening temperature, measured according to DIN 53,460, which is 5°-40° C. lower than that of the component A, with or without (C) effective amounts of conventional assistants.

We claim: 
     
       1. An elastomeric thermoplastic molding material containing (A) from 5 to 50 parts by volume of a partially or completely crystalline thermoplastic polymer comprising a nylon, a polyester or a polyacetal having a melting point of above 160° C., as a coherent phase, and   (B) from 95 to 50 parts by volume of one or more cross-linked elastomeric polymers which are prepared by emulsion polymerization, are dispersed in the component A and have a glass transistion temperature Tg of below -10° C., the sum of A and B being 100 parts by volume, wherein the elastomeric polymer B consists of esters of (meth) acrylic acid of not more than 15 carbon atoms and from 5 to 20% by weight of comonomers which possess 2 or more double bonds per molecule and can be cross-linked with free radicals, with the proviso that the mixture of A and B has a Vicat softening temperatures, measured according to DIN 53,460, which is 5°-40° C lower than that of the component A, with or without   (C) effective amounts of conventional assistants.   
     
     
       2. An impact-resistant thermoplastic molding material as claimed in claim 1, wherein the elasomeric polymer B has a swelling index, in toluene, of from 2 to 8. 
     
     
       3. An impact-resistant thermoplastic molding material as claimed in claim 1, wherein the elastomeric polymer B possesses, on the surface of the particles, molecular groups which promote adhesion to the molecules of the polymer A. 
     
     
       4. An impact-resistant thermoplastic molding material as claimed in claim 1, wherein the elastomeric polymer B contains carboxyl, carboxylic ester, carboxamide or epoxide groups, at least at the surface of the particles. 
     
     
       5. An impact-resistant thermoplastic molding material as claimed in claim 1, which is obtained by thorough mixing of a melt of the polymer A with an aqueous dispersion of the elastomeric polymer B, with the simultaneous removal of the water vaporized during this procedure. 
     
     
       6. A process for the preparation of a thermoplastic molding material as claimed in claim 1, wherein a melt of the polymer A is mixed thoroughly with an aqueous dispersion of the elastomeric polymer B and at the same time the water vaporized in this procedure is removed.